STUDIES ON THE PATHOGENESIS OF RABIES IN INSECTIVOROUS BATS

Abstract

Studies on the pathogenesis of rabies in 2 species of experimentally infected insectivorous Chiroptera, the Mexican free-tailed bat (Tadarida mexicana) and the little brown bat (Myotis lucifugus) provided evidence that brown adipose tissue may serve as an extraneural site for storage and multiplication of rabies virus. Virus was demonstrated in the brown fat of 22% of Mexican free-tailed bats shown to be infected by viral assay in white Swiss mice; infection was most evident 20 to 40 days after intramuscular inoculation of virus. Rabies virus was widely distributed in the little brown Myotis 9 to 26 days following inoculation. Virus was demonstrated in the brown fat of 30% of the experimentally infected Myotis and was isolated more frequently from this tissue than from the salivary gland indicating that in a susceptible host brown adipose tissue may be as frequent a site of viral proliferation as salivary gland. It is suggested that brown adipose tissue provides a mechanism by which these animals may serve as reservoirs for this agent in nature.